Hi Georg,
Thanks for reaching out to us with your question.
First off, I would like to apologize for the delay answering.
We are currently experiencing a higher level of requests than usual. Please rest assured that we are working hard at correcting this situation. We appreciate your patience while we try to normalize things.
Events is a custom post type, which is actually quite similar to posts and pages. Beside the generic data it needs to store also a lot of additional data in the post_meta table. When deleting an event that extra data also needs to be deleted and that is what causes it to take longer.
What you can do is skip the trash part. Here’s an article about the different ways to do that.
I hope this helps. Let me know if you have any further questions.
Cheers,
Andras